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1.
J Wildl Dis ; 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38679922

RESUMO

Rabies is a highly virulent viral disease that has been associated with large-scale population declines of the endangered African wild dog (Lycaon pictus). Rabies vaccination may be a valuable conservation tool in this species, but studies indicate that a single dose does not always confer protective immunity. We examined 47 serum samples from 22 captive African wild dogs (sampled opportunistically for other purposes) to assess whether serum antibody levels after vaccination correlated with the number of doses received and whether other factors affected outcomes. Results of the fluorescent antibody virus neutralization test showed that median antibody titers were 0.085 IU/mL prevaccination, 0.660 IU/mL after a single vaccination, and 22.150 IU/mL after a booster vaccination. Antibody titers above 0.5 IU/mL, internationally accepted as the threshold for seroconversion, were found in none of the samples taken prevaccination, 66.67% of samples taken after primary vaccination, and 90.90% of samples collected after booster vaccination. This study illustrates the probable protective benefit a rabies booster vaccination may provide in African wild dogs and serves as a basis for future research to improve vaccination protocols contributing to the conservation of this endangered species.

2.
Viruses ; 16(4)2024 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-38675958

RESUMO

Reverse zoonotic transmission events of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been described since the start of the pandemic, and the World Organisation for Animal Health (WOAH) designated the detection of SARS-CoV-2 in animals a reportable disease. Eighteen domestic and zoo animals in Great Britain and Jersey were tested by APHA for SARS-CoV-2 during 2020-2023. One domestic cat (Felis catus), three domestic dogs (Canis lupus familiaris), and three Amur tigers (Panthera tigris altaica) from a zoo were confirmed positive during 2020-2021 and reported to the WOAH. All seven positive animals were linked with known SARS-CoV-2 positive human contacts. Characterisation of the SARS-CoV-2 variants by genome sequencing indicated that the cat was infected with an early SARS-CoV-2 lineage. The three dogs and three tigers were infected with the SARS-CoV-2 Delta variant of concern (B.1.617.2). The role of non-human species in the onward transmission and emergence of new variants of SARS-CoV-2 remain poorly defined. Continued surveillance of SARS-CoV-2 in relevant domestic and captive animal species with high levels of human contact is important to monitor transmission at the human-animal interface and to assess their role as potential animal reservoirs.


Assuntos
Animais de Zoológico , COVID-19 , SARS-CoV-2 , Tigres , Animais , Cães , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/classificação , COVID-19/transmissão , COVID-19/epidemiologia , COVID-19/veterinária , COVID-19/virologia , Tigres/virologia , Gatos , Animais de Zoológico/virologia , Inglaterra/epidemiologia , Humanos , Filogenia , Doenças do Cão/virologia , Doenças do Cão/epidemiologia , Doenças do Cão/transmissão , Zoonoses/virologia , Zoonoses/transmissão , Zoonoses/epidemiologia
3.
J Virol Methods ; 319: 114769, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37391076

RESUMO

Rabies virus (RABV) causes a fatal encephalitis that can be prevented through timely vaccination. The levels of virus neutralising antibodies against rabies virus induced by vaccination can be measured using the fluorescent antibody virus neutralisation (FAVN) test. Following incubation of live virus with sera, this method involves the fixation of cell monolayers and staining of rabies virus-specific antigen using fluorescein isothiocyanate (FITC) -conjugated antibody to enable visualisation of rabies virus antigen using a fluorescence microscope. To simplify this procedure, a fluorescent recombinant rabies virus was constructed using reverse genetics by inserting the gene for the mCherry fluorescent protein in front of the ribonucleoprotein gene of the SAD B-19 genome and replacing its glycoprotein with that of the Challenge Virus Standard (CVS)-11 RABV strain to ensure antigenic authenticity with the FAVN. This new recombinant virus (termed mCCCG) expressed the mCherry protein to high levels enabling direct observation of infected cells. In vitro growth kinetics of mCCCG were indistinguishable from that of CVS-11. The stability of the recombinant virus was assessed by sequencing several passages of the rescued virus and only minor changes were detected. Comparative assessment of the virus neutralisation test using mCherry producing virus (NTmCV) against the FAVN demonstrated that test results were equivalent to each other; therefore, mCCCG can be used as an alternative to CVS-11 for measuring antibody titres against the rabies virus. The use of NTmCV removes the need for expensive antibody conjugates and significantly reduces assay time. This would be particularly beneficial for RABV serological assessment in resource limited settings. Moreover, the reading of the plates can be automatically using a cell imaging reader.


Assuntos
Vacina Antirrábica , Vírus da Raiva , Raiva , Humanos , Vírus da Raiva/genética , Anticorpos Antivirais , Testes de Neutralização/métodos , Antígenos Virais , Anticorpos Neutralizantes
4.
J Extracell Vesicles ; 11(11): e12247, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36377074

RESUMO

Vaccine platforms enable fast development, testing, and manufacture of more affordable vaccines. Here, we evaluated Generalized Modules for Membrane Antigens (GMMA), outer membrane vesicles (OMVs) generated by genetically modified Gram-negative bacteria, as a vaccine platform for viral pathogens. Influenza A virus hemagglutinin (HA), either physically mixed with GMMA (HA+STmGMMA mix), or covalently linked to GMMA surface (HA-STmGMMA conjugate), significantly increased antigen-specific humoral and cellular responses, with HA-STmGMMA conjugate inducing further enhancement than HA+STmGMMA mix. HA-STmGMMA conjugate protected mice from lethal challenge. The versatility for this platform was confirmed by conjugation of rabies glycoprotein (RABVG) onto GMMA through the same method. RABVG+STmGMMA mix and RABVG-STmGMMA conjugate exhibited similar humoral and cellular response patterns and protection efficacy as the HA formulations, indicating relatively consistent responses for different vaccines based on the GMMA platform. Comparing to soluble protein, GMMA was more efficiently taken up in vivo and exhibited a B-cell preferential uptake in the draining lymph nodes (LNs). Together, GMMA enhances immunity against viral antigens, and the platform works well with different antigens while retaining similar immunomodulatory patterns. The findings of our study imply the great potential of GMMA-based vaccine platform also against viral infectious diseases.


Assuntos
Antígenos Virais , Vacinas , Camundongos , Animais , Membranas
5.
J Gen Virol ; 103(11)2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36748502

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19) in humans, has a wide host range, naturally infecting felids, canids, cervids, rodents and mustelids. Transmission of SARS-CoV-2 is universally accepted to occur via contact with contaminated secretions from the respiratory epithelium, either directly or indirectly. Transmission via droplet nuclei, generated from a cough or sneeze, has also been reported in several human and experimental animal scenarios. However, the role of droplet transmission at the human-animal interface remains to be fully elucidated. Here, the ferret infection model was used to investigate the routes of infection for the SARS-CoV-2 beta variant (B.1.351). Ferrets were exposed to droplets containing infectious SARS-CoV-2, ranging between 4 and 106 µm in diameter, simulating larger droplets produced by a cough from an infected person. Following exposure, viral RNA was detected on the fur of ferrets, and was deposited onto environmental surfaces, as well as the fur of ferrets placed in direct contact; SARS-CoV-2 remained infectious on the fur for at least 48 h. Low levels of viral RNA were detected in the nasal washes early post-exposure, yet none of the directly exposed, or direct-contact ferrets, became robustly infected or seroconverted to SARS-CoV-2. In comparison, ferrets intranasally inoculated with the SARS-CoV-2 beta variant became robustly infected, shedding viral RNA and infectious virus from the nasal cavity, with transmission to 75 % of naive ferrets placed in direct contact. These data suggest that larger infectious droplet nuclei and contaminated fur play minor roles in SARS-CoV-2 transmission among mustelids and potentially other companion animals.


Assuntos
COVID-19 , Animais , Humanos , SARS-CoV-2 , Furões , Tosse , Partículas e Gotas Aerossolizadas , RNA Viral/genética
6.
Viruses ; 13(12)2021 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-34960647

RESUMO

Lagos bat lyssavirus (LBV) comprising four lineages (A, B, C and D) can potentially cause the fatal disease rabies. Although LBV-B was initially isolated in Nigeria in 1956, there is no information on LBV lineages circulating in Nigeria. This study was undertaken for the first time to measure the neutralizing antibodies against four lineages of LBVs in straw-colored fruit bats (Eidolon helvum) in Makurdi, Nigeria. Serum samples (n = 180) collected during two periods (November 2017-March 2018 and November 2018-March 2019) from terminally bled bats captured for human consumption were tested using a modified fluorescent antibody virus neutralization (mFAVN) assay. A high proportion of bat sera (74%) neutralized at least one lineage of LBV (with reciprocal titers from 9 to >420.89) and most of them neutralized LBV-A (63%), followed by LBV-D (49%), LBV-C (45%) and LBV-B (24%). The majority of positive sera (75%, n = 100) neutralized multiple LBV lineages while the remaining 25% (n = 33) neutralized only a single lineage, i.e., LBV-A (n = 23), LBV-D (n = 8) and LBV-C (n = 2). None exclusively neutralized LBV-B. The results suggest that exposure to LBV is common in E. helvum and that LBV-A (but not LBV-B) is likely to be circulating in this region of Nigeria.


Assuntos
Anticorpos Antivirais/sangue , Quirópteros/virologia , Lyssavirus/imunologia , Raiva/virologia , Infecções por Rhabdoviridae/virologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Feminino , Humanos , Lyssavirus/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Nigéria/epidemiologia
7.
PLoS Negl Trop Dis ; 15(5): e0009431, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34014930

RESUMO

Human fatalities caused by rabies are rarely reported in Jordan; however, domestic animals are more likely to fall victim to rabies compared to wild animals, at least this is the case in Jordan due to the presence of canine rabies. In this study, twelve brain samples from domestic and wild animals suspected of being infected with rabies virus from different regions of Jordan were collected during 2019. Seven of them tested positive using the fluorescent antibody test and real-time SYBR RT-PCR assay. Five specimens were from stray dogs and two from foxes. The whole genome sequences were obtained from the positive samples. Sequence analysis showed that one dog virus from Al Quwaysimah city located in Amman governorate, was closely related to an Israeli strain belonging to a Cosmopolitan ME1a clade. The genomes of the remaining six viruses (four from dogs and two from foxes) collected from different areas of Jordan were genetically-related to each other and clustered together with sequences from Iran and Turkey; all belong to Cosmopolitan ME2 clade. These sequences were analyzed with six other Jordanian rabies virus nucleoprotein (N) gene sequences available in the public database, five of them belong to ME1a clade and one belongs to ME1b clade. Rabies virus whole genome data is scarce across the Middle East. This study provides a better understanding of the molecular epidemiology of rabies virus in the region.


Assuntos
Doenças do Cão/epidemiologia , Vírus da Raiva/genética , Raiva/veterinária , Animais , Encéfalo/virologia , Doenças do Cão/virologia , Cães , Raposas/virologia , Jordânia/epidemiologia , Epidemiologia Molecular , Filogenia , Raiva/epidemiologia , Vírus da Raiva/classificação , Sequenciamento Completo do Genoma
8.
Viruses ; 13(4)2021 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-33924168

RESUMO

SARS-CoV-2 virus was first detected in late 2019 and circulated globally, causing COVID-19, which is characterised by sub-clinical to severe disease in humans. Here, we investigate the serological antibody responses to SARS-CoV-2 infection during acute and convalescent infection using a cohort of (i) COVID-19 patients admitted to hospital, (ii) healthy individuals who had experienced 'COVID-19 like-illness', and (iii) a cohort of healthy individuals prior to the emergence of SARS-CoV-2. We compare SARS-CoV-2 specific antibody detection rates from four different serological methods, virus neutralisation test (VNT), ID Screen® SARS-CoV-2-N IgG ELISA, Whole Antigen ELISA, and lentivirus-based SARS-CoV-2 pseudotype virus neutralisation tests (pVNT). All methods were able to detect prior infection with COVID-19, albeit with different relative sensitivities. The VNT and SARS-CoV-2-N ELISA methods showed a strong correlation yet provided increased detection rates when used in combination. A pVNT correlated strongly with SARS-CoV-2 VNT and was able to effectively discriminate SARS-CoV-2 antibody positive and negative serum with the same efficiency as the VNT. Moreover, the pVNT was performed with the same level of discrimination across multiple separate institutions. Therefore, the pVNT is a sensitive, specific, and reproducible lower biosafety level alternative to VNT for detecting SARS-CoV-2 antibodies for diagnostic and research applications. Our data illustrate the potential utility of applying VNT or pVNT and ELISA antibody tests in parallel to enhance the sensitivity of exposure to infection.


Assuntos
Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19/métodos , COVID-19/diagnóstico , SARS-CoV-2/imunologia , Idoso , Anticorpos Neutralizantes/sangue , COVID-19/sangue , COVID-19/imunologia , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Lentivirus/genética , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Reprodutibilidade dos Testes , SARS-CoV-2/isolamento & purificação , Sensibilidade e Especificidade , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia
9.
PLoS Negl Trop Dis ; 14(12): e0008898, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33320860

RESUMO

Rabies is a fatal neurologic disease caused by lyssavirus infection. Bats are important natural reservoir hosts of various lyssaviruses that can be transmitted to people. The epidemiology and pathogenesis of rabies in bats are poorly understood, making it difficult to prevent zoonotic transmission. To further our understanding of lyssavirus pathogenesis in a natural bat host, an experimental model using straw-colored fruit bats (Eidolon helvum) and Lagos bat virus, an endemic lyssavirus in this species, was developed. To determine the lowest viral dose resulting in 100% productive infection, bats in five groups (four bats per group) were inoculated intramuscularly with one of five doses, ranging from 100.1 to 104.1 median tissue culture infectious dose (TCID50). More bats died due to the development of rabies after the middle dose (102.1 TCID50, 4/4 bats) than after lower (101.1, 2/4; 101.1, 2/4) or higher (103.1, 2/4; 104.1, 2/4) doses of virus. In the two highest dose groups, 4/8 bats developed rabies. Of those bats that remained healthy 3/4 bats seroconverted, suggesting that high antigen loads can trigger a strong immune response that abrogates a productive infection. In contrast, in the two lowest dose groups, 3/8 bats developed rabies, 1/8 remained healthy and seroconverted and 4/8 bats remained healthy and did not seroconvert, suggesting these doses are too low to reliably induce infection. The main lesion in all clinically affected bats was meningoencephalitis associated with lyssavirus-positive neurons. Lyssavirus antigen was detected in tongue epithelium (5/11 infected bats) rather than in salivary gland epithelium (0/11), suggesting viral excretion via the tongue. Thus, intramuscular inoculation of 102.1 TCID50 of Lagos bat virus into straw-colored fruit bats is a suitable model for lyssavirus associated bat rabies in a natural reservoir host, and can help with the investigation of lyssavirus infection dynamics in bats.


Assuntos
Quirópteros/virologia , Lyssavirus , Infecções por Rhabdoviridae/veterinária , Animais , Reservatórios de Doenças , Raiva/veterinária , Raiva/virologia , Infecções por Rhabdoviridae/virologia
10.
PLoS Negl Trop Dis ; 12(10): e0006870, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30372438

RESUMO

BACKGROUND: Estimates of current global rabies mortality range from 26,000 to 59,000 deaths per annum. Although pre-exposure prophylaxis using inactivated rabies virus vaccines (IRVs) is effective, it requires two to three doses and is regarded as being too expensive and impractical for inclusion in routine childhood immunization programmes. METHODOLOGY/ PRINCIPAL FINDINGS: Here we report the development of a simian-adenovirus-vectored rabies vaccine intended to enable cost-effective population-wide pre-exposure prophylaxis against rabies. ChAdOx2 RabG uses the chimpanzee adenovirus serotype 68 (AdC68) backbone previously shown to achieve pre-exposure protection against rabies in non-human primates. ChAdOx2 differs from AdC68 in that it contains the human adenovirus serotype 5 (AdHu5) E4 orf6/7 region in place of the AdC68 equivalents, enhancing ease of manufacturing in cell lines which provide AdHu5 E1 proteins in trans. We show that immunogenicity of ChAdOx2 RabG in mice is comparable to that of AdC68 RabG and other adenovirus serotypes expressing rabies virus glycoprotein. High titers of rabies virus neutralizing antibody (VNA) are elicited after a single dose. The relationship between levels of VNA activity and rabies virus glycoprotein monomer-binding antibody differs after immunization with adenovirus-vectored vaccines and IRV vaccines, suggesting routes to further enhancement of the efficacy of the adenovirus-vectored candidates. We also demonstrate that ChAdOx2 RabG can be thermostabilised using a low-cost method suitable for clinical bio-manufacture and ambient-temperature distribution in tropical climates. Finally, we show that a dose-sparing effect can be achieved by formulating ChAdOx2 RabG with a simple chemical adjuvant. This approach could lower the cost of ChAdOx2 RabG and other adenovirus-vectored vaccines. CONCLUSIONS/ SIGNIFICANCE: ChAdOx2 RabG may prove to be a useful tool to reduce the human rabies death toll. We have secured funding for Good Manufacturing Practice- compliant bio-manufacture and Phase I clinical trial of this candidate.


Assuntos
Adenovirus dos Símios/genética , Portadores de Fármacos , Profilaxia Pré-Exposição/métodos , Vacina Antirrábica/imunologia , Raiva/prevenção & controle , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Custos e Análise de Custo , Estabilidade de Medicamentos , Feminino , Vetores Genéticos , Esquemas de Imunização , Camundongos , Vacina Antirrábica/administração & dosagem , Vacina Antirrábica/economia , Vacina Antirrábica/genética , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/economia , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
11.
PLoS Negl Trop Dis ; 12(3): e0006311, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29505617

RESUMO

Rabies is a fatal neurologic disease caused by lyssavirus infection. People are infected through contact with infected animals. The relative increase of human rabies acquired from bats calls for a better understanding of lyssavirus infections in their natural hosts. So far, there is no experimental model that mimics natural lyssavirus infection in the reservoir bat species. Lagos bat virus is a lyssavirus that is endemic in straw-colored fruit bats (Eidolon helvum) in Africa. Here we compared the susceptibility of these bats to three strains of Lagos bat virus (from Senegal, Nigeria, and Ghana) by intracranial inoculation. To allow comparison between strains, we ensured the same titer of virus was inoculated in the same location of the brain of each bat. All bats (n = 3 per strain) were infected, and developed neurological signs, and fatal meningoencephalitis with lyssavirus antigen expression in neurons. There were three main differences among the groups. First, time to death was substantially shorter in the Senegal and Ghana groups (4 to 6 days) than in the Nigeria group (8 days). Second, each virus strain produced a distinct clinical syndrome. Third, the spread of virus to peripheral tissues, tested by hemi-nested reverse transcriptase PCR, was frequent (3 of 3 bats) and widespread (8 to 10 tissues positive of 11 tissues examined) in the Ghana group, was frequent and less widespread in the Senegal group (3/3 bats, 3 to 6 tissues positive), and was rare and restricted in the Nigeria group (1/3 bats, 2 tissues positive). Centrifugal spread of virus from brain to tissue of excretion in the oral cavity is required to enable lyssavirus transmission. Therefore, the Senegal and Ghana strains seem most suitable for further pathogenesis, and for transmission, studies in the straw-colored fruit bat.


Assuntos
Encéfalo/patologia , Quirópteros/virologia , Lyssavirus/classificação , Lyssavirus/fisiologia , Raiva/veterinária , Animais , Anticorpos Antivirais/sangue , Reservatórios de Doenças , Interações Hospedeiro-Patógeno , Imuno-Histoquímica , Neurônios/patologia , Neurônios/virologia , Raiva/epidemiologia
12.
Sci Rep ; 8(1): 1865, 2018 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-29382871

RESUMO

Ticks host a wide range of zoonotic pathogens and are a significant source of diseases that affect humans and livestock. However, little is known about the pathogens associated with bat ticks. We have collected ectoparasites from bat carcasses over a seven year period. Nucleic acids (DNA and RNA) were extracted from 296 ticks removed from bats and the species designation was confirmed in all ticks as Argas (Carios) vespertilionis. A subset of these samples (n = 120) were tested for the presence of zoonotic pathogens by molecular methods. Babesia species, Rickettsia spp., within the spotted fever group (SFG), and Ehrlichia spp. were detected in ticks removed from 26 bats submitted from 14 counties across England. The prevalence of Rickettsia spp. was found to be highest in Pipistrellus pipistrellus from southern England. This study suggests that the tick species that host B. venatorum may include the genus Argas in addition to the genus Ixodes. As A. vespertilionis has been reported to feed on humans, detection of B. venatorum and SFG Rickettsia spp. could present a risk of disease transmission in England. No evidence for the presence of flaviviruses or Issyk-Kul virus (nairovirus) was found in these tick samples.


Assuntos
Argas/genética , Babesia/genética , Quirópteros/microbiologia , Quirópteros/parasitologia , Rickettsia/genética , Infestações por Carrapato/veterinária , Zoonoses/epidemiologia , Animais , Argas/classificação , Babesia/classificação , Inglaterra , Genes Bacterianos , Interações Hospedeiro-Patógeno , RNA Ribossômico 16S/genética , Rickettsia/classificação , Infestações por Carrapato/epidemiologia , Zoonoses/microbiologia
13.
Infect Ecol Epidemiol ; 7(1): 1332935, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28804595

RESUMO

Introduction: Grenada is a rabies endemic country, where terrestrial rabies is maintained in the small Indian mongoose (Herpestes auropunctatus). The role of bats in the epidemiology of rabies in Grenada is unknown. A 1974 report described one rabies virus positive Jamaican fruit bat (Artibeus jamaicensis), and a high seroprevalence in this species. In the current study, the natural exposure to rabies virus in Grenadian bats was re-evaluated. It is postulated that bats serve as a natural rabies reservoir, probably circulating a bat-specific rabies virus variant. Material and methods: Bats were trapped in 2015 in all six parishes of Grenada using mist- and hand nets. For the detection of rabies virus in brain tissue, the direct fluorescent antibody test (dFAT) and the reverse transcription polymerase chain reaction (RT-PCR) were used. Serum neutralizing antibodies were determined using the fluorescent antibody virus neutralization test (FAVN). Results and discussion: Brain tissue and sera from 111 insectivorous and frugivorous bats belonging to four species were tested (52 Artibeus jamaicensis, two Artibeus lituratus, 33 Glossophaga longirostris, 24 Molossus molossus). Rabies virus antigen and genomic RNA were not detected in brain tissues. Rabies virus neutralizing antibodies were detected in the sera of eight A. jamaicensis in four of the six parishes. Bats in Grenada continue to show natural exposure to rabies virus. As rabies virus was not isolated in this study, serology alone is not sufficient to determine the strain of rabies virus circulating in A. jamaicensis bats in Grenada. Conclusion: Artibeus jamaicensis appears to play a role as a reservoir bat species, which is of public health concern in Grenada. Dispersion of bats to neighboring islands is possible and serological bat surveys should be initiated in these neighboring states, especially in those areas that are free of rabies in terrestrial mammals.

14.
Vaccine ; 34(48): 5959-5967, 2016 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-27997343

RESUMO

Despite the availability of safe and effective human vaccines, rabies remains a global threat, with an estimated 60,000 human deaths annually attributed to rabies. Pre-exposure prophylaxis against rabies infection is recommended for travelers to countries where rabies is endemic, and also for those with a higher risk of exposure. In this study, the rabies-specific neutralising antibody responses in a cohort of rabies-vaccinated recipients over a period of twenty years have been assessed. In particular, the antibody response to primary vaccinations and boosters, and the waning of antibody post primary vaccination and post booster were investigated. The significance of gender, age at vaccination, vaccine manufacturer and vaccination intervals were also evaluated. These data confirm that rabies vaccination can elicit a neutralising antibody response that can remain at detectable levels for a number of years, without additional booster vaccinations. The antibody response following both primary vaccination and booster was significantly influenced by the gender of the subject (p=0.002 and 0.03 respectively), with supportive data that suggests an effect by the make of vaccine administered following primary vaccination, with significantly higher VNA titres observed for one vaccine manufactured prior to 2006 (p<0.001) in a small subset of recipients (n=5). Additionally, the decay rate was demonstrated through the overall decline in antibody titre for all individuals, which was a 37% and 27% reduction per 2-fold change in time following primary and booster vaccination respectively. Individuals within older age groups demonstrated a significantly faster decline in antibody titre following the primary vaccination course (p=0.012). Rate of decline in antibody titre was also significantly influenced by the vaccine make following primary course (p<0.001). The assessment of neutralising antibody titre decline has also provided an insight into the most appropriate timing for booster administration, and enabled the prediction of long term titres from post-vaccination antibody titres.


Assuntos
Esquemas de Imunização , Profilaxia Pré-Exposição , Vacina Antirrábica/imunologia , Raiva/imunologia , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Estudos de Coortes , Doenças Endêmicas/prevenção & controle , Feminino , Humanos , Imunização Secundária , Injeções Intradérmicas , Masculino , Raiva/prevenção & controle , Vacina Antirrábica/administração & dosagem , Fatores Sexuais , Fatores de Tempo , Viagem , Potência de Vacina
15.
Parasit Vectors ; 9: 203, 2016 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-27075661

RESUMO

BACKGROUND: Theileria spp. are tick-borne protozoan parasites of the Phylum Apicomplexa, Order Piroplasmida that infect a wide range of wild and domestic animals. In Great Britain, Theileria spp. have been reported from livestock associated with transmission by the tick Haemaphysalis punctata. However, these reports have not been associated with disease. This study has investigated the cause of a disease outbreak accompanied by mortality in a flock of sheep grazing reclaimed marshland in north Kent. FINDINGS: A polymerase chain reaction-reverse line blot assay indicated the presence of Theileria spp. in blood samples from five animals. Subsequent testing with a pan-piroplasm PCR of a larger panel of blood samples detected a piroplasm amplicon in 19 of 21 sheep submitted from the affected flock. Automated sequencing confirmed that these amplicons shared 99-100% identity with T. luwenshuni. CONCLUSIONS: The clinical and PCR data suggest infection with T. luwenshuni was associated with disease and mortality in this flock.


Assuntos
Doenças dos Ovinos/parasitologia , Theileria/isolamento & purificação , Theileriose/parasitologia , Animais , Ovinos , Doenças dos Ovinos/transmissão , Theileria/genética , Theileria/fisiologia , Theileriose/transmissão , Carrapatos/parasitologia , Carrapatos/fisiologia , Reino Unido
16.
PLoS Negl Trop Dis ; 8(10): e3251, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25330178

RESUMO

In Grenada, West Indies, rabies is endemic, and is thought to be maintained in a wildlife host, the small Indian mongoose (Herpestes auropunctatus) with occasional spillover into other hosts. Therefore, the present study was undertaken to improve understanding of rabies epidemiology in Grenada and to inform rabies control policy. Mongooses were trapped island-wide between April 2011 and March 2013 and examined for the presence of Rabies virus (RABV) antigen using the direct fluorescent antibody test (dFAT) and PCR, and for serum neutralizing antibodies (SNA) using the fluorescent antibody virus neutralization test (FAVN). An additional cohort of brain samples from clinical rabies suspects submitted between April 2011 and March 2014 were also investigated for the presence of virus. Two of the 171 (1.7%) live-trapped mongooses were RABV positive by FAT and PCR, and 20 (11.7%) had SNAs. Rabies was diagnosed in 31 of the submitted animals with suspicious clinical signs: 16 mongooses, 12 dogs, 2 cats and 1 goat. Our investigation has revealed that rabies infection spread from the northeast to the southwest of Grenada within the study period. Phylogenetic analysis revealed that the viruses from Grenada formed a monophyletic clade within the cosmopolitan lineage with a common ancestor predicted to have occurred recently (6-23 years ago), and are distinct from those found in Cuba and Puerto Rico, where mongoose rabies is also endemic. These data suggest that it is likely that this specific strain of RABV was imported from European regions rather than the Americas. These data contribute essential information for any potential rabies control program in Grenada and demonstrate the importance of a sound evidence base for planning interventions.


Assuntos
Controle de Doenças Transmissíveis/métodos , Reservatórios de Doenças/veterinária , Herpestidae/virologia , Vírus da Raiva/genética , Raiva/epidemiologia , Animais , Antígenos Virais/imunologia , Gatos , Cuba/epidemiologia , Cães , Cabras/virologia , Granada/epidemiologia , Filogenia , Filogeografia , Porto Rico/epidemiologia , Raiva/virologia , Vacina Antirrábica , Vírus da Raiva/classificação , Vírus da Raiva/imunologia
17.
PLoS Negl Trop Dis ; 8(5): e2835, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24784117

RESUMO

In Germany, rabies in bats is a notifiable zoonotic disease, which is caused by European bat lyssaviruses type 1 and 2 (EBLV-1 and 2), and the recently discovered new lyssavirus species Bokeloh bat lyssavirus (BBLV). As the understanding of bat rabies in insectivorous bat species is limited, in addition to routine bat rabies diagnosis, an enhanced passive surveillance study, i.e. the retrospective investigation of dead bats that had not been tested for rabies, was initiated in 1998 to study the distribution, abundance and epidemiology of lyssavirus infections in bats from Germany. A total number of 5478 individuals representing 21 bat species within two families were included in this study. The Noctule bat (Nyctalus noctula) and the Common pipistrelle (Pipistrellus pipistrellus) represented the most specimens submitted. Of all investigated bats, 1.17% tested positive for lyssaviruses using the fluorescent antibody test (FAT). The vast majority of positive cases was identified as EBLV-1, predominately associated with the Serotine bat (Eptesicus serotinus). However, rabies cases in other species, i.e. Nathusius' pipistrelle bat (Pipistrellus nathusii), P. pipistrellus and Brown long-eared bat (Plecotus auritus) were also characterized as EBLV-1. In contrast, EBLV-2 was isolated from three Daubenton's bats (Myotis daubentonii). These three cases contribute significantly to the understanding of EBLV-2 infections in Germany as only one case had been reported prior to this study. This enhanced passive surveillance indicated that besides known reservoir species, further bat species are affected by lyssavirus infections. Given the increasing diversity of lyssaviruses and bats as reservoir host species worldwide, lyssavirus positive specimens, i.e. both bat and virus need to be confirmed by molecular techniques.


Assuntos
Quirópteros/virologia , Vigilância em Saúde Pública/métodos , Animais , Encéfalo/virologia , Alemanha/epidemiologia , Lyssavirus/classificação , Lyssavirus/genética , Lyssavirus/isolamento & purificação , Raiva/epidemiologia , Raiva/veterinária , Raiva/virologia , Estudos Retrospectivos , Zoonoses/epidemiologia , Zoonoses/virologia
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